Some questions about the bitcoin system

[DataPlumber]

The address is obtained from ripemd160(sha256(pubkey)).[...] https://en.bitcoin.it/wiki/Technical_background_of_Bitcoin_addresses

...Aaaand I stand corrected.  Thanks!

[DannyHamilton]

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I'm a little lost with the BTC addresses and their respective private keys. How this work, one is for receiving and the other for sending?
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You don't really need to know how all these technical details work to use bitcoin. All the well known wallets take care of these details for you.  However, the information you've been given so far is a good generalization of what happens.

[zdavidi]

In response to the wallet question, I recently read something about the most secure way to create a wallet is by flash-booting into Ubuntu or Redhat and installing/creating a bitcoin wallet onto the temporary boot. Then, generating a receive coins address and saving that address on some kind of physical manifestation (micro SD) or writing it down.
1. How would one be able to back-up the wallet data and transport it in a digital format so it can later be re-opened, and re-secured?
2. How does one load backed-up wallet data on a machine with existing wallet data already? (Like I have a wallet for my PC and a wallet for my Laptop, how would I take the wallet data from my Laptop, and load the data on my desktop?)
3. When the secured wallet is offline, wouldn't the transaction be one-way? Granted wallet data can't be maintained?

Sort of like driving an 18-wheeler..............down a 1-lane dirt road..................and finding a dead end............................with no where to turn around.